The expression of m1-m3 muscarinic receptor mRNAs in rat brain following REM sleep deprivation.

We used in situ hybridization histochemistry to study the effects of REM sleep deprivation on m1-m3 muscarinic receptor mRNA expression in the rat brain. REM sleep deprivation for 72 h did not affect m1 receptor mRNA expression. However, we found significantly increased m3 receptor mRNA expression in the pontine nuclei and nucleus accumbens-bed nucleus of the stria terminalis region of REM sleep-deprived rats compared with controls. Paradoxically, we found significantly decreased m2 receptor mRNA expression in the pontine nuclei of REM sleep-derived rats vs controls. The present findings implicate these structures in the cholinergic effector pathways of REM sleep, although the type and magnitude of the effects of these structures on REM sleep may vary with different receptor subtypes.